Image forming apparatus and control method of stapling unit thereof

ABSTRACT

An image forming apparatus and a control method of a stapling unit thereof, the method including selecting a first mode to apply stapling to previously output media, setting options about the first mode, stacking the previously output media on a feeding tray, transporting the stacked previously output media via a transporting path of the image forming apparatus, and applying the stapling to the previously output media according to the options of the first mode. Also provided is an image forming apparatus capable of stapling and discharging a previously output medium without a process of forming an image when a user selects a menu for stapling the previously output medium, thereby avoiding waste of paper and improving convenience for a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Korean Patent Application No. 10-2008-0105521, filed on Oct. 27, 2008 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

Apparatuses and methods consistent with the present general inventive concept relate to an image forming apparatus and a control method of a stapling unit thereof, and more particularly, to an image forming apparatus capable of stapling a previously output medium on which an image is formed and a control method of a stapling unit thereof.

2. Description of the Related Art

An image forming apparatus forms an image to be printed on a print medium. The image forming apparatus may include a printer, a copying machine, a facsimile, a multi-function peripheral having two or more functions, etc.

Recently, a demand for an office automation system in which the image forming apparatus performs the functions of the scanner, the facsimile, etc. as well as a function of printing a document like a multi-function peripheral has been on the rise. Accordingly, the image forming apparatus has been gradually developed to have higher performance, thereby extending its effective functions.

For example, the image forming apparatus may be provided with an electric stapler to perform a function of stapling printed or copied output materials.

To use the function of stapling such an output material, a user selects a printing or copying menu and then selects a stapling option in the selected menu. Then, the image forming apparatus forms images on recording media supplied from a feeding tray and carries out the stapling function after a process of forming an image on the last recording medium is completed, thereby discharging the stapled recording media.

However, if a user is not familiar with using the menu of the image forming apparatus, he/she may finish the printing without selecting the stapling option.

In this case, if a user wants to staple the previously output media previously discharged with images formed thereon, a user has to count documents one by one and manually staples them, or go back over all printing processes including the process of forming the images.

Thus, when a user does not select the stapling option by mistake during the printing setting or when it needs to only staple the previously output materials, going back over all the printing processes may waste paper and it is inconvenient for a user to carry out the manual stapling.

SUMMARY

Accordingly, example embodiments of the present general inventive concept provide an image forming apparatus capable of stapling and discharging a previously output medium without a process of forming an image when a user selects a menu for only stapling the previously output medium, and a control method of a stapling unit thereof, thereby avoiding waste of paper and improving convenience for a user.

Additional embodiments of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

Example embodiments of the present general inventive concept can be achieved by providing a method of controlling a stapling unit mounted to an image forming apparatus, the method comprising selecting a first mode to apply stapling to previously output media, setting options about the first mode, stacking the previously output media on a feeding tray, transporting the stacked previously output media via a transporting path of the image forming apparatus, and applying the stapling to the previously output media according to the options of the first mode.

The setting the options about the first mode may comprise selecting a feeding tray on which the previously output media to undergo the stapling are stacked, and setting a stapling direction and a stapling position of at least one of the previously output media, whether or not the previously output media are sorted.

The transporting the previously output media via a transporting path of the image forming apparatus may comprise transporting the previously output media via a transporting path of the image forming apparatus without a process of forming an image.

The feeding tray may comprise at least one of a feeding cassette, a manual feeding tray, and an option cassette.

The transporting path may comprise at least one of a transporting path to form an image and a transporting path of an automatic document feeder (ADF).

Another embodiment of the present general inventive concept can be achieved by providing a method of controlling a stapling unit of an image forming apparatus, the method comprising selecting a first mode to apply stapling to previously output media, sensing whether the previously output media are inserted in a medium discharging unit, and applying the stapling to the sensed previously output media. Here, the method may further comprise aligning the previously output media inserted in the medium discharging unit.

Still another embodiment of the present general inventive concept can be achieved by providing an image forming apparatus comprising a user interface to select a first mode to apply stapling to previously output media, and to set options about the first mode, a feeding tray on which the previously output media are stacked, a transporting unit to transport the stacked previously output media, a stapling unit to apply the stapling to the previously output media, and a controller to control the transporting unit to transport the previously output media stacked on the feeding tray to a transporting path of the image forming apparatus depending on the selected first mode, and to control the stapling unit to apply the stapling the transported previously output media according to the options of the first mode.

The options set about the first mode may comprise a selection of a feeding tray on which the previously output media to undergo the stapling are stacked, and a setting of a stapling direction and a stapling position of at least one of the previously output media, whether or not the previously output media are sorted.

The controller may control the transporting unit to transport the previously output media via a transporting path of the image forming apparatus without a process of forming an image.

The feeding tray may comprise at least one of a feeding cassette, a manual feeding tray, and an option cassette.

The transporting path may comprise at least one of a transporting path to form an image and a transporting path of an automatic document feeder (ADF).

The controller may control rollers relevant to the transport of the previously output media on the basis of the selected first mode.

Still another embodiment of the present general inventive concept can be achieved by providing an image forming apparatus comprising a user interface to select a first mode to apply stapling to previously output media, a medium discharging unit comprising a medium sensing unit to sense the previously output media and a stapling unit to apply the stapling to the sensed previously output media, and a controller to control the stapling unit to apply the stapling the sensed previously output media if it is determined that the previously output media is inserted in the medium discharging unit. Here, the medium discharging unit may further comprise a medium aligning unit to align the inserted previously output media.

Yet another embodiment of the present general inventive concept can be achieved by providing a stapling unit of an image forming apparatus, the stapling unit comprising a user interface to select a stapling operation after the image forming apparatus outputs a printed media, and a controller to control the stapling unit to apply a stapling operation to the previously outputted printed media according to the selection.

Additional previously outputted printed media can be added to the previously outputted printed media, and the controller can control the stapling unit to apply the stapling operation to the additional previously outputted printed media and the previously outputted printed media.

The user interface can be connected to the image forming apparatus via a wired or wireless network.

Yet another embodiment of the present general inventive concept can be achieved by providing a method of controlling a stapling unit of an image forming apparatus, the method comprising selecting a stapling operation after the image forming apparatus outputs a printed media, and controlling the stapling unit to apply a stapling operation to the previously outputted printed media according to the selecting.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other embodiments of the present general inventive concept will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of an image forming apparatus according to an exemplary embodiment of the present general inventive concept;

FIGS. 2 and 3 illustrate an image forming apparatus according to an exemplary embodiment of the present general inventive concept;

FIG. 4 illustrates a selection screen in a first mode according to an exemplary embodiment of the present general inventive concept; and

FIGS. 5 and 6 are flowcharts of controlling a stapling unit of an image forming apparatus according to exemplary embodiments of the present general inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.

FIG. 1 is a block diagram of an image forming apparatus 100 according to an exemplary embodiment of the present general inventive concept, and FIGS. 2 and 3 illustrate the image forming apparatus 100 according to an exemplary embodiment of the present general inventive concept. The image forming apparatus 100 may include a printer, a copying machine, a facsimile, a multi-function peripheral having two or more functions, etc.

Meanwhile, the image forming apparatus 100 according to an exemplary embodiment of the present general inventive concept can be connectable with an external apparatus such as a host apparatus 200. A user may have access to the image forming apparatus 100 through log-in to the host apparatus 200, and can give a print command with a stapling option and print data to the image forming apparatus 100.

The image forming apparatus 100 according to an exemplary embodiment of the present general inventive concept can print out the print data onto at least one sheet of paper.

As illustrated in FIG. 1, the image forming apparatus 100 can include a medium feeding unit 110, an image forming unit 120, a fusing unit 130, a transporting unit 140, a medium discharging unit 150, a user interface 160, a display unit 170, a communication unit 180, and a controller 190. The medium discharging unit 150 may include a stapling unit 151, a medium sensing unit 152, and a medium aligning unit 153.

The medium feeding unit 110 can provide a recording medium (paper), on which an image will be printed, supplied from at least one feeding tray 111. The medium feeding unit 110 can include the feeding tray 111, an automatic document feeder (ADF, not illustrated), a duplex automatic document feeder (DADF, not illustrated), and a pickup roller 112 to pick up the recording medium. The feeing tray 111 can include at least one of a feeding cassette, a manual feeding tray, and an optional tray.

According to another exemplary embodiment of the present general inventive concept, as illustrated in FIG. 3, the image forming apparatus 100 may further include an exclusive stapling tray 113, on which the recording medium is stacked, as the optional tray provided at one side of the image forming apparatus 100.

In this embodiment, a previously output medium P1, P2 can be stacked on at least one of the feeing tray 111 and the exclusive stapling tray 113 of the image forming apparatus 100. The previously output medium P1, P2 can be a document on which an image has previously been formed, and does not need a separate process of forming an image.

The image forming unit 120 can print out an image based on print data to at least one medium in response to a print command. Here, the print can include print for a copy after scanning a document, print for received fax data, and print for print data received from an external host apparatus 200 such as a server or stored in an interior (hard disk drive (HDD) or exterior (universal serial bus (USB) memory) of the image forming apparatus 100.

Referring to FIGS. 2 and 3, the image forming unit 120 can include an exposure unit 121, a developing unit 122, and a transferring unit 123.

The exposure unit 121 can emit light to form a latent image based on print data. The developing unit 122 can provide a toner to form a visual image. Then, the visual image can be transferred to the recording medium while the recording medium supplied from the medium feeding unit 110 passes between the developing unit 122 and the transferring unit 123.

The fusing unit 130 can fix the image, formed by the image forming unit 110 and transferred to the recording medium, to the recording medium by thermo-compression. The fusing unit 130 may include a heat roller internally provided with a heating means (e.g., heater, not illustrated) to generate heat, and a compression roller being in close contact with the heat roller to form a fixing nip. The heat roller and the compression roller can apply heat and pressure to an image formed by the image forming unit 120 while rotated and engaged by a predetermined pressure, thereby fixing the image on the recording medium. The heating means (heater) provided in the heat roller may be achieved by a halogen lamp, a heat wire, an induction heater, etc. According to an exemplary embodiment of the present general inventive concept, the process of forming an image may include a fixing process.

The transporting unit 140 can transport the previously output medium supplied from the medium feeding unit 110 to pass through the image forming unit 120 and the fusing unit 130, which may be achieved by a transporter belt. In this embodiment as illustrated in FIG. 3, the previously output medium fed from the exclusive stapling tray 113 may be transported without passing through the image forming unit 120 and the fusing unit 130.

The medium discharging unit 150 can include a discharging roller to discharge the previously output medium on which an image is printed to the outside of the image forming apparatus 100. The medium discharging unit 150 may include the stapling unit 151 to apply a post-processing function to the discharged paper. In addition, the medium discharging unit 150 may include at least one of a stacker, a finisher, sorter and a puncher to stack or sort the discharged paper or apply post-processing functions to the sorted paper.

According to an exemplary embodiment of the present general inventive concept, the medium discharging unit 150 may further include the medium sensing unit 152 and the medium aligning unit 153. The medium aligning unit 153 may be achieved by a paper guide placed in parallel with or perpendicularly to a discharging direction of the paper so as to align the paper.

The user interface 160 can receive a command from a user. The user interface 160 may include a key button (hereinafter, referred to as “hard key” or a “key pad”) provided in the image forming apparatus 100, or a graphic user interface (GUI) produced by execution of a printer driver or a separate application and displayed on the display unit 170 to thereby allow a user to input a command through the GUI.

The image forming apparatus 100 may have a first mode and a second mode as operation modes according to whether or not an image is formed on the paper. In the first mode, the previously output media P1 can be stacked on the feeding tray 111 and can be then transported to a transporting path of the image forming apparatus 100 without the process of forming an image, thereby being stapled and discharged to the outside. In the second mode, the recording media stacked on the feeding tray 111 can be fed and undergo the process of forming an image, thereby being discharged after post-processes corresponding to a setting option.

Through the user interface 160 of the image forming apparatus 100, the first mode (e.g., a stapling only mode) in which the previously output media P1 stacked on the feeding tray 111 can be stapled can be selected, and options about the first mode can be set. Here, the options may include a choice of a feeding tray on which the previously output media to undergo stapling are stacked, and setting of at least one of the number of previously output media, whether or not the previously output media are sorted, and a stapling direction and a stapling position.

As necessary, without setting the options about the first mode, the image forming apparatus 100 may apply stapling to all the previously output media stacked on a predetermined feeding tray.

Meanwhile, the first mode of the image forming apparatus 100 in this embodiment may include an execute-now mode and a tray stapling mode.

In the execute now mode, the previously output media P3 inserted by a user in the medium discharging unit 150 in a direction reverse to a medium discharging direction can be sensed and undergo the stapling (refer to FIG. 2).

In the tray stapling mode, the previously output media stacked on the feeding tray 111, the ADF, etc. can be transported to pass through the transporting path without the processes of forming and fixing an image, and then undergo the stapling. If the tray stapling mode is selected, at least one feeding tray on which the previously output media to undergo the stapling are stacked may be selected through the user interface 160. Also, in the tray stapling mode, the previously output media stacked on the exclusive stapling tray 113 may be directly transported to the medium discharging unit 150 and undergo the stapling (refer to FIG. 3).

A user may perform log-in, i.e., input identification (ID) code assigned to his/her account and password through the user interface 160. Here, the log-in may include administrator mode log-in allowed to set and modify all environments without any separate limitation on access. If the log-in is performed as general users or an administrator, the image forming apparatus 100 can implement authentication and permission with regard to the log-in.

According to an exemplary embodiment of the present general inventive concept, the user interface 120 may be achieved by a remote user interface (RUI) displayed in the host apparatus 200 such as a personal computer (PC) or the like remotely connectable to the image forming apparatus 100 through the communication unit 180. If the RUI is employed as the user interface 120, a user may log in the host apparatus 200 connected to the image forming apparatus 100 and can select the first mode and the options of the image forming apparatus 100.

The display unit 170 may illustrate a user setting and operating states of the image forming apparatus 100, and may display a GUI screen to receive various commands from a user. The display unit 170 may include a thin film transistor-liquid crystal display (TFT-LCD) and a driver (not illustrated) to drive the TFT-LCD.

The display unit 170 can display either of the execute-now mode or the tray stapling mode to be selectable if a user selects the first mode, and can illustrate an assigned screen of a stapling option corresponding to the selected mode. Thus, the image forming apparatus 100 can apply the stapling to the previously output media according to the stapling option set by a user.

FIG. 4 illustrates a selection screen in a first mode according to an exemplary embodiment of the present general inventive concept. As illustrated in FIG. 4, if a user selects a first mode icon 10 involving a stapling direction, the image forming apparatus 100 can display various stapling options so that the stapling options can be set corresponding to the selected first mode, and can apply the stapling to the previously output media stacked on the feeding tray concerned according to the set stapling option.

The communication unit 180 can perform data communication with an external apparatus including the host apparatus 200, a server, etc. The communication unit 180 may include a wire/wireless communication module connectable with the external apparatus such as the host apparatus 200 locally or through a network based on a predetermined protocol, a universal serial bus (USB) port connectable with a portable storage medium such as a USB memory, etc. Also, the communication unit 180 may include a fax communication module that converts data read by a scanning unit (not illustrated) into a fax signal and transmits it or receives a fax signal. Further, the communication unit 180 can perform a scan-to-host or scan-to-server function to transmit the scan data to the external apparatus such as the host apparatus 200 or the server, or to perform a scan-to-email function or the like function to transmit the scan data to the exterior.

Meanwhile, the image forming apparatus 100 may further include a storage (not illustrated) to store setting information about the first mode, print data received from the outside, a scan image produced by the scanning unit, and/or various information such as user authorization information, user authentication information, and user registration information set according to user's account. The storage may include an internal storage medium such as an HDD, or an external or portable storage medium such as a USB memory, a memory card (memory stick, compact flash (CF) card, a multi-media card (MMC)).

The controller 190 can perform general control for the image forming apparatus 100. Specifically, if the first mode in which the stapling is applied to the previously output media is selected through the user interface 170, the controller 190 can receive the setting options about the first mode selected through the user interface 170, can control the transporting unit 140 to transport the previously output media so that the previously output media stacked on the feeding tray 111 pass through the transporting path of the image forming apparatus, and can control the transported previously output media to undergo the stapling according to the setting options of the first mode. Then, the controller 190 can control the medium discharging unit 150 to discharge the stapled previously output media.

Here, when the first mode is selected, the controller 190 can control the image forming unit 120 and the fusing unit 130 not to apply the processes of forming and fixing an image to the previously output media passing through the transporting path, respectively. That is, in response to the selected first mode, the controller 190 can control the rollers relevant to only the transport of the previously output medium, excluding an organic photo conductor (OPC) drum, a developing drum, a charging roller (e.g., corona charging), a toner supplying roller, a laser scanning unit (LSU), a cleaning roller (e.g., blade), a fixer, etc. Also, the transporting path may include at least one of a transporting path to form an image and a transporting path for an automatic document feeder (ADF).

The controller 190 can control the stapling unit 151 to carry out the stapling according to the selected first mode and options. Here, the controller 190 can control the medium aligning unit 153 to align the previously output media transported to the discharging unit 150 through the medium sensing unit 152, and then can staple the aligned previously output media.

For example, if the tray stapling mode in the first mode is selected, a user can set the options such as a choice of a feeding tray on which the previously output media to undergo the stapling are stacked, the number of previously output media to be stapled, whether or not the previously output media are sorted, a stapling direction, a stapling position, etc.

The image forming apparatus 100 can discharge the previously output media P1 from the relevant feeding tray 111 according to the set stapling options, to thereby transport, staple and discharge the previously output media P1 without forming and fixing an image (refer to FIG. 2).

Here, if the selected feeding tray is the exclusive stapling tray 113 as illustrated in FIG. 3, the image forming apparatus 100 can discharge and transport the previously output media P2 from the exclusive stapling tray 113, to thereby apply the stapling to the previously output media P2 and discharge them to the outside.

On the other hand, if the execute now mode is selected while selecting the first mode, for example, if a user selects the execute now mode and inserts the previously output media P3 in the medium discharging unit 150 in the direction reverse to the medium discharging direction, the controller 190 can control the medium sensing unit 152 to sense whether or not the previously output media P3 are inserted, and can control the stapling unit 151 to apply the stapling to the sensed previously-output medium P3. Here, the controller 190 may control the medium aligning unit 153 to align the previously output medium P3 inserted according to a user's selections.

In the meantime, when the transport of the previously output media stacked on the selected feeding tray 111 is completed, the image forming apparatus 100 may allow a user to select whether to additionally stack the previously output media on the relevant feeding tray 111 and carry out the stapling. Here, if a user selects the stack of the previously output media through the user interface 160 and additionally stacks the previously output media on the relevant feeding tray 111, the controller 190 can control the transporting unit 140 to transport the added previously output media and to apply the stapling once to all the transported previously output media when the added previously output media can be completely transported, thereby discharging the previously output media.

Also, if the number of transported previously output media reaches a stapling limit number of the image forming apparatus 100, it can be possible to select whether to divisionally apply the stapling to the transported previously output media and perform the stapling two or more times according to the selected result.

In the image forming apparatus with the foregoing configuration, the stapling control will be described below with reference to FIGS. 5 and 6.

FIG. 5 is a flowchart of controlling a stapling unit of the image forming apparatus according to an exemplary embodiment of the present general inventive concept.

Referring to FIG. 5, at operation S110 a user may select the first mode, in which the stapling is applied to the previously output media, through the user interface 160. Here, the selected first mode may be the tray stapling mode. If the first mode is selected at the operation S110, the options may be set with regard to the first mode at operation S120.

That is, a user may select the feeding tray 111 or 113, on which the previously output media to be stapled are stacked, through the user interface 160. Here, the selected feeding tray may include at least one of a feeding cassette, a manual feeding tray and an option cassette. Further, the feeding tray may further include at least one of the exclusive stapling tray 113 and the automatic document feeder (ADF).

Also, a user may set at least one of the number of previously output media, whether or not the previously output media are sorted, the stapling direction and the stapling position. Alternatively, the image forming apparatus 100 may apply the stapling to all the previously output media stacked on the selected feeding tray without the processes of setting the number of previously output media, whether or not the previously output media are sorted, the stapling direction and the stapling position in the operation S120.

At operation S130, a user can stack the previously output media P1 or P2 on the feeding tray selected in the operation S120.

At operation S140, the controller 190 can transport the previously output media stacked in the operation S130 to the transporting path of the image forming apparatus 100 in response to the first mode set in the operations S110 and S120 without the process of forming an image. Here, the transporting path may include at least one of a transporting path to form an image and a transporting path of the automatic document feeder (ADF).

If the transport of the operation S140 is completed with regard to the previously output media stacked on the feeding tray selected through the user interface 160 in the operation S120, at operation S150 the image forming apparatus 100 may allow a user to select whether to additionally stack the previously output media and implement the stapling.

At operation S160, according to the selection in the operation S150 the controller 190 can apply the stapling to the previously output media transported in the operation S140 on the basis of the options set in the operation S120 and can discharge the media. Here, the controller 190 may align the previously output media transported in the operation S140 and then apply the stapling to the aligned previously output media.

If it is selected that the previously output media are additionally stacked to be stapled and a user adds the previously output media to the relevant feeding tray, at operation S170 the controller 190 can transport the added previously output media without the process of forming an image.

At operation S160, the controller 190 can apply the stapling to the previously output media transported in the operation S140 and S160 on the basis of the options set in the operation S120 and can discharge the media.

Meanwhile, the image forming apparatus 100 may apply the stapling to the previously output media inserted in the medium discharging unit 150 without the process of transporting the previously output media.

FIG. 6 is a flowchart of a method of controlling a stapling unit of the image forming apparatus 100 according to another exemplary embodiment of the present general inventive concept.

Referring to FIG. 6, at operation S210 a user may select the first mode, in which the stapling can be applied to the previously output media, through the user interface 160. Here, the selected first mode can include the execute now mode.

At operation S220, the medium sensing unit 152 can sense whether the previously output media P3 are inserted in the medium discharging unit 150 in response to the selection of the operation S210.

At operation S230, the medium aligning unit 153 can align the sensed previously output media if it is sensed in the operation S220 that the previously output media P3 are inserted in the medium discharging unit 150.

At operation S240, the controller 190 can perform the stapling with regard to the previously output media inserted in the operation S220 and can discharge the stapled previously output media.

Accordingly, even though a user does not select the stapling option by mistake during the printing setting or it needs to only staple the previously output materials, the image forming apparatus 100 according to an exemplary embodiment of the present general inventive concept can use the first mode to perform the stapling via the existing transporting path with regard to the previously output materials, thereby reducing wasteful printing and providing convenience to a user.

As described above, the present general inventive concept provides an image forming apparatus capable of stapling and discharging a previously output medium without a process of forming an image when a user selects a menu for only stapling the previously output medium, and a control method of a stapling unit thereof, thereby avoiding waste of paper and improving convenience for a user.

Although a few exemplary embodiments of the present general inventive concept have been illustrated and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents. 

1. A method of controlling a stapling unit mounted to an image forming apparatus, the method comprising: selecting a first mode to apply stapling to previously output media; setting options about the first mode; stacking the previously output media on a feeding tray; transporting the stacked previously output media via a transporting path of the image forming apparatus; and applying the stapling to the previously output media according to the options of the first mode.
 2. The method according to claim 1, wherein the setting the options about the first mode comprises: selecting a feeding tray on which the previously output media to undergo the stapling are stacked; and setting a stapling direction and a stapling position of at least one of the previously output media, whether or not the previously output media are sorted.
 3. The method according to claim 1, wherein the transporting the previously output media via a transporting path of the image forming apparatus comprises transporting the previously output media via a transporting path of the image forming apparatus without a process of forming an image.
 4. The method according to claim 1, wherein the feeding tray comprises at least one of a feeding cassette, a manual feeding tray, and an option cassette.
 5. The method according to claim 1, wherein the transporting path comprises at least one of a transporting path to form an image and a transporting path of an automatic document feeder (ADF).
 6. A method of controlling a stapling unit of an image forming apparatus, the method comprising: selecting a first mode to apply stapling to previously output media; sensing whether the previously output media are inserted in a medium discharging unit; aligning the previously output media inserted in the medium discharging unit and applying the stapling to the sensed previously output media.
 7. An image forming apparatus comprising: a user interface to select a first mode to apply stapling to previously output media is selected, and to set options about the first mode; a feeding tray on which the previously output media are stacked; a transporting unit to transport the stacked previously output media; a stapling unit to apply the stapling to the previously output media; and a controller to control the transporting unit to transport the previously output media stacked on the feeding tray to a transporting path of the image forming apparatus depending on the selected first mode, and to control the stapling unit to apply the stapling to the transported previously output media according to the options of the first mode.
 8. The image forming apparatus according to claim 7, wherein the options set about the first mode comprise a selection of a feeding tray on which the previously output media to undergo the stapling are stacked, and setting a stapling direction and a stapling position of at least one of the previously output media, whether or not the previously output media are sorted.
 9. The image forming apparatus according to claim 7, wherein the controller controls the transporting unit to transport the previously output media via a transporting path of the image forming apparatus without a process of forming an image.
 10. The image forming apparatus according to claim 7, wherein the feeding tray comprises at least one of a feeding cassette, a manual feeding tray, and an option cassette.
 11. The image forming apparatus according to claim 7, wherein the transporting path comprises at least one of a transporting path to form an image and a transporting path of an automatic document feeder (ADF).
 12. The image forming apparatus according to claim 7, wherein the controller controls rollers relevant to the transport of the previously output media on the basis of the selected first mode.
 13. An image forming apparatus, comprising: a user interface to select a first mode to apply stapling to previously output media; a medium discharging unit comprising a medium sensing unit to sense the previously output media and a stapling unit to apply the stapling to the sensed previously output media; and a controller to control the stapling unit to apply the stapling the sensed previously output media if it is determined that the previously output media is inserted in the medium discharging unit.
 14. The image forming apparatus according to claim 13, wherein the medium discharging unit further comprises a medium aligning unit to align the inserted previously output media.
 15. A stapling unit of an image forming apparatus, the stapling unit comprising: a user interface to select a stapling operation after the image forming apparatus outputs a printed media; and a controller to control the stapling unit to apply a stapling operation to the previously outputted printed media according to the selection.
 16. The stapling unit of claim 15, wherein additional previously outputted printed media are added to the previously outputted printed media, and the controller controls the stapling unit to apply the stapling operation to the additional previously outputted printed media and the previously outputted printed media.
 17. A method of controlling a stapling unit of an image forming apparatus, the method comprising: selecting a stapling operation after the image forming apparatus outputs a printed media; and controlling the stapling unit to apply a stapling operation to the previously outputted printed media according to the selecting, wherein additional previously outputted printed media are added to the previously outputted printed media, and wherein the controlling the stapling unit comprises controlling the stapling unit to apply the stapling operation to the additional previously outputted printed media and the previously outputted printed media. 